Hi! From the pictures, your frogs look like Australian White's Tree Frogs. If so, here is an excellent care article for them: Frog Forum - White's Tree Frog Care - Litoria caerulea. A Herp Vet will probably have knowledge to check out and treat your frog. Still, here are a few things that probably contributed to the problem and some recommendations. By the way; it's just a matter of time until the other frog shows same neurological symptoms and if not helped, you could end up losing both .

The hospital type enclosure and the veterinary visit recommended by Lynn are still required. These are just frog basic needs that need to be corrected. Good luck and let us know what the veterinary said !

Quote Originally Posted by k8lin View Post
1. Im not sure of the exact size of the encloser, the shop owner recommended it for 2 frogs
Just measure the enclosure's length, width, and height and let us know

3. Im not sure what the humidity is of how to check it.
Need to get a hygrometer at a pet store. Digital units are more accurate than analogs. For White's ventilation is very important and humidity around 65% is OK.

4. The temperature sits between 20 and 30°c. that’s what the shop owner recommended.
Temperature should be 30C during day with a few degrees drop to around 24C at night.

5. I use fresh filtered water only in the water bowl, the guy I got them from never told me mist them, he’s never done for his frogs and their fine.
Filtered water could still have chloramines and/or be over processed. Either one of those items could lead to Toxic Out Syndrome (TOS) with symptoms like you are experiencing. Recommend use dechlorinated tap water (Seachem Prime works good) for frogs water dish and for preparing any substrate like shredded coco, etc. You can use distilled water to spray enclosure since it does not leave water marks; but avoid spraying frogs with it.

8. The main food source is crickets (that’s wat I was told to fed them)
Crickets should be sized same as distance between frog's eyes and gut loaded with veggies (carrots and lettuce) and cereals (oats and cherios). Can also feed them similar sized Dubia roaches if available there. To better monitor feeding, can use a small glass bowl around 5 cm. height and crickets will not get out.

9. I was never told to give the frogs any kind of supplements. I got them almost a year ago and have only every given them crickets and they’ve been fine. Until now.
Yes, but now one of them is very sick and lack of CA/D3 is part of the issue. When frog CA levels drop; they actually draw CA from their bones in order to support physiological needs. That makes bones soft and eventually deformed. The problem is called Metabolic Bone Disease. Recommend get CA/D3 and vitamin supplements (Repashy or RepCal are good) and dust the frog's foods. Here is a schedule to follow: http://www.frogforum.net/food-feeder...schedules.html.

19. I frog isn’t handle much, because I don’t want it to absorb anything bad. But when I do handle it I always wash my hands with anti-bacterial hand wash, then dry them then wash my hands again to ensure I hve remover all germs, oils, soap ect and I make sure my hands are still wet when I pick them up
After washing and rinsing hands should do a final rinse with dechlorinated tap water.

21. I change the water every 2 days, and clean the tank with plain filtered water every 3-4 weeks or earlier if its required. Although its due for a clean atm but I haven’t yet because I want to kno what wrong with the frog before I do.
Also the frog has not left the water since I first posted this.
Water dish should be refilled daily with dechlorinated tap even if it looks unused.